Production of iron



Patented June 14, '1938 Erich Faust and Eberhard Jung,

Herrenwyk,

Lubeck, Germany, assignors to Hochofenwerk Liibeck Aktiengesellschaft,Herrenwyk,

Germany, a company No Drawing. Application rial No. 118,017. In 1936 7Claims.

This invention relates to improvements in the production of iron and isparticularly concerned profitable use for taining titanium,

for example, or Japanese certain magnetic iron ores consuch as are foundin Norway titanium-iron sands for example and, on the other hand, it wasintended to produce crude irons containing titanium. Al-

though these attempts were successful in avoiding the high viscosity ofthe slag,which frequently occurs with a normal slag-composition due toincrease of the TiOz content, by working with highly acid slag (forinstance, 46% SiOz+AlzOa and 44% CaO+MgO), they did not succeed in0btaining, in continuous operation, appreciable contents ot titanium inthe crude iron, in particular contents exceeding 0.6% (Cf. Osann,Lehrbuch der Eisenhiittenkunde, published by W. Engelmann, 2nd edition1923, pages 643 and 644) A crude" iron with a high titanium-content wasfirst successfully produced a few years ago in the electricalblast-furnace (Bremanger A. S., Norway).

It has now been found that it is possible to produce crude iron with ahigher content of titanium, exceeding 0.6%, in continuous operation andwithout difficulty in the coke blast-furnace provided that certainconditions are observed in regard to the slag-composition andfurnace-tem-' perature. With a slag which consists, as is usual,

of calcium silicates, experience shows that an appreciable reduction ofthermore there is also narily diflicult fusibility trouble with thefurnace;

TiOz does not occur; furthe danger of extra-ordiand consequently of If,however, a slag is employed which consists predominatingly of calciumaluminates, that is predominatingiy of compounds of CaO and A1203, thenit is possible to reduce considerable quantities of the titanic oxideand to transfer it into the crude iron. A

condition is that high"hearth-temperatures, which amount to more than1600 C. andfrequently up to 1800 C. and more, are operated with. In thisfashion, it. is possible to transfer up to 60% of the titanium-contentof the mixture or charge into the crude iron. If the process isconducted, in the known manner, with a lower hearth-temperature, thensubstantial quantities iron; on the contrary,

it is not possible to introduce of titanium into the crude by far thepredominating Lubeck. of Germany December 28, 1936, Se- Germany February6,

(Cl. 7M1) part of any titanium present in the mixture goes into theslag.

In order to ensure the desired slag-composition, which should as far aspossible lie within the limits of 4-25% SlOz, 35-55% CaO and -60% A1203,it is preferable to work with bauxite as ore. As this raw materialcontains, say, 3-5% of TiOz, an addition to the mixture of titaniumores, such for example as ilmenite or rutile, is not necessary or isonly necessary to a very limited extent. In this manner, a high degreeof economy is ensured for the process.

Moreover, it has been found, on the one hand, that it is necessary, forthe good quality of the crude iron produced, to work with largequantitles of slag, which may amount to three times the quantity ofcrude iron and, on the other hand, that the regular operation of thefurnace is not endangered by slag-difliculties in spite of this largequantity of slag.

Since bauxite, as an ore, contains only a little iron, it has provedadvantageous to add scrap-- iron to the mixture in order to increase theyield of crude iron. The (la-oxidizing action of the lime-aluminate slagand of the high titanium content of the crude iron nevertheless ensuresfor the iron a very excellent quality which is especially suitable forvery highly stressed castings. The following examples may be given toindicate the composition of the mixture.

EXAMPLE 1 Mixture with ilm enite In both cases, .a crude iron with08-13% or titanium is obtained, depending upon the furnace-temperature.

We claim:--

1. In the process for the production of a crude iron containing morethan 0.6% of titanium in a coke blast furnace by employment of a chargemixture of bauxite containing titanium, limestone and coke and byemployment of a slag containing more than 50% of lime-aluminates andworking at a furnace temperature between 1600 C. to 1800 C., the step ofworking with a. high slag to iron ratio, which exceeds 1:1 and may evenbe as high as 3:1 ratio.

2. The process for the production of a crude iron containing more than0.6% of titanium in the coke blast furnace comprising charging a mixtureof bauxite and titanium ores, limestone and coke, employing a slagcontaining more than 50% of lime-aluminates and working at a furnacetemperature between 1600 C. and 1800 C.

with a slag to iron ratio between 1:1 and 3:1. 3. The process of claim 1in which scrap is added to the charge mixture.

ERICH FAUST. EBERHARD JU N G.

